Medical probe with biopsy stylet

ABSTRACT

A medical probe apparatus comprising a catheter having a stylet guide housing with at least one stylet port in a side thereof and a stylet guide for directing a flexible stylet outward through at least one stylet port and through intervening tissue to targeted tissues. The stylet guide has a biopsy sample device or other tissue manifesting device at the distal end thereof to gather tissue or perform other operations at the point of the desired tissue such as emitting electromagnetic energy as ablative power to target tissues. 
     One embodiment of the biopsy sample stylet includes a hollow core sampler including a biopsy needle apparatus for gathering sample tissue. The hollow core sampler has a sharpened end for facilitating the penetration into and gathering of the sample tissue. A second embodiment of the biopsy sample stylet includes a harpoon-like sample stylet when the sharp tip thereof allows for easy entry into the target tissue. The sharpened barbed side opening allows for certain desired tissue to be sampled to be drawn into the side opening for individual cell gathering or complete sample excise or gathering of the desired tissue. The third embodiment is a clam shell or alligator type biopsy jaw device whereby the sharpened biopsy tip thereof allows a tissue sample to be clipped or cut upon activation of the stylet jaws. Still another embodiment comprises a biopsy knife device in conjunction with an electromagnetic emitter for selective tissue sampling or electromagnetic heat ablation, or both, of selected tissue.

RELATIONSHIP TO COPENDING APPLICATION

This application is a continuation of application Ser. No. 08/155,975,filed on Nov. 19, 1993, now U.S. Pat. No. 5,470,308; which is acontinuation-in-part of copending application Ser. No. 07/929,638, filedAug. 12, 1992 now abandoned; which is a continuation-in-part ofapplication Ser. No. 08/012,370, filed Feb. 2, 1993 now U.S. Pat. No.5,370,675; which is a continuation-in-part of application Ser. No.08/062,364, filed May 13, 1993 now U.S. Pat. No. 5,435,805; the entirecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention is directed to unique methods and apparatus forpenetrating body tissues to a target tissue for purposes of obtaining abiopsy tissue sample, and, optionally, for other medical purposes suchas tissue destruction and fluid substance delivery, for example. Thedevice penetrates tissue to the precise target selected in order toobtain the sample and optionally to deliver energy to the tissue and/ordeliver substances. It limits this activity to the precise preselectedsite, thereby minimizing trauma to normal surrounding tissue andachieving a greater medical benefit. This apparatus is a catheter-likedevice for positioning a biopsy and optional treatment assembly in thearea or organ selected for examination and medical treatment with one ormore stylets in the catheter, mounted for extension from a stylet portin the side of the catheter through surrounding tissue to the tissuetargeted for medical activity.

BACKGROUND OF THE INVENTION

Treatment of cellular tissues usually requires direct contact of targettissue with a medical instrument, usually by surgical proceduresexposing both the target and intervening tissue to substantial trauma.Often, precise placement of a treatment probe is difficult because ofthe location of a target tissue in the body, or the proximity of thetarget tissue to easily damaged, critical body organs, nerves, or othercomponents.

Benign prostatic hypertrophy or hyperplasia (BPH), for example, is oneof the most common medical problems experienced by men over 50 yearsold. Urinary tract obstruction due to prostatic hyperplasia has beenrecognized since the earliest days of medicine. Hyperplastic enlargementof the prostate gland often leads to compression of the urethra,resulting in obstruction of the urinary tract and the subsequentdevelopment of symptoms including frequent urination, decrease inurinary flow, nocturia, pain, discomfort, and dribbling. The associationof BPH with aging has been shown by the incidence of BPH to exceed 50%in men over 50 years of age and increases in incidence to over 75% inmen over 80 years of age. Symptoms of urinary obstruction occur mostfrequently between the ages of 65 and 70 when approximately 65% of menin this age group have prostatic enlargement.

Currently there is no nonsurgical method of treatment of BPH which hasproven to be effective. In addition, the surgical procedures availableare not totally satisfactory. Currently patients suffering from theobstructive symptoms of this disease are provided with few options:continue to cope with the symptoms (i.e., conservative management),submit to drug therapy at early stages, or submit to surgicalintervention. More than 430,000 patients per year in the United Statesundergo surgery for removal of prostatic tissue. These represent lessthan five percent of men exhibiting clinical significant symptoms.

Those suffering from BPH are often elderly men, many with additionalhealth problems which increase the risk of surgical procedures. Surgicalprocedures for the removal of prostatic tissue are associated with anumber of hazards including anesthesia associated morbidity, hemorrhage,coagulopathies, pulmonary emboli and electrolyte imbalances. Theseprocedures performed currently can also lead to cardiac complications,bladder perforation, incontinence, infection, urethral or bladder neckstricture, retention of prostatic chips, retrograde ejaculation, andinfertility. Due to the extensive invasive nature of the currenttreatment options for obstructive uropathy, the majority of patientsdelay definitive treatment of their condition. This circumstance canlead to serious damage to structures secondary to the obstructive lesionin the prostate (bladder hypertrophy, hydronephrosis, dilation of thekidney pelves, chronic infection, dilation of ureters, etc.) which isnot without significant consequences. In addition, a significant numberof patients with symptoms sufficiently severe to warrant surgicalintervention are poor operative risks and are poor candidates forprostatectomy. In addition, younger men suffering from BPH who do notdesire to risk complications such as infertility are often forced toavoid surgical intervention. Thus the need, importance and value ofimproved surgical and non-surgical methods for treating BPH isunquestionable.

High-frequency currents are used in electrocautery procedures forcutting human tissue, especially when a bloodless incision is desired orwhen the operating site is not accessible with a normal scalpel butpresents an access for a thin instrument through natural body openingssuch as the esophagus, intestines, or urethra. Examples include theremoval of prostatic adenomas, bladder tumors, or intestinal polyps. Insuch cases, the high-frequency current is fed by a surgical probe intothe tissue to be cut. The resulting dissipated heat causes boiling andvaporization of the cell fluid at this point, whereupon the cell wallsrupture and the tissue is separated.

Destruction of cellular tissues in situ has been used in the treatmentof many diseases and medical conditions alone or as an adjunct tosurgical removal procedures. It is often less traumatic than surgicalprocedures and may be the only alternative where other procedures areunsafe. Ablative treatment devices have the advantage of using anelectromagnetic energy which is rapidly dissipated and reduced to anon-destructive level by conduction and convection forces of circulatingfluids and other natural body processes.

Microwave, radiofrequency, acoustical (ultrasound) and light energy(laser) devices, and tissue destructive substances have been used todestroy malignant, benign and other types of cells and tissues from awide variety of anatomic sites and organs. Tissues treated includeisolated carcinoma masses and, more specifically, organs such as theprostate, glandular and stromal nodules characteristic of benignprostate hyperplasia. These devices typically include a catheter orcannula which is used to carry a radiofrequency electrode or microwaveantenna through a duct to the zone of treatment and apply energydiffusely through the duct wall into the surrounding tissue in alldirections. Severe trauma is often sustained by the duct wall duringthis cellular destruction process, and some devices combine coolingsystems with microwave antennas to reduce trauma to the ductal wall. Fortreating the prostate with these devices, for example, heat energy isdelivered through the walls of the urethra into the surrounding prostatecells in an effort to kill the tissue constricting the urethra. Lightenergy, typically from a laser, is delivered to prostate tissue targetsites by "burning through" the wall of the urethra. Healthy cells of theduct wall and healthy tissue between the nodules and duct wall are alsoindiscriminately destroyed in the process and can cause unnecessary lossof some prostate function. Furthermore, the added cooling function ofsome microwave devices complicates the apparatus and requires that thedevice be sufficiently large to accommodate this cooling system.

Application of liquids to specific tissues for medical purposes islimited by the ability to obtain delivery without traumatizingintervening tissue and to effect a delivery limited to the specifictarget tissue. Localized chemotherapy, drug infusions, collageninjections, or injections of agents which are then activated by light,heat or chemicals would be greatly facilitated by a device which couldconveniently and precisely place a fluid supply catheter opening at thespecific target tissue.

If the operating surgeon desires to take a sample of selected tissue, abiopsy device is utilized. Biopsy devices are well known. U.S. Pat. No.3,595,217 to Rheinfrank, issued Jul. 27, 1971, describes a prostatebiopsy method wherein the physician's finger is guided into the rectumwhereupon a biopsy needle is then inserted through the guide andtransrectally into the prostate gland. U.S. Pat. No. 3,598,108 toJamishidi, issued Aug. 10, 1971, describes a biopsy needle with aninternal removable sleeve member and stylet. U.S. Pat. No. 4,396,021 toBaumgartner, issued Aug. 2, 1983, describes a prostate biopsy deviceusing a sheath whereupon a harpoon tipped sampling unit is utilized.U.S. Pat. No. 4,600,014 to Beraha, issued Jul. 15, 1986, discloses acore sample biopsy needle arrangement that includes a handle and a guidetube. U.S. Pat. No. 4,989,614 to Dejter, issued Feb. 9, 1991, disclosesa fine-needle aspiration biopsy device. U.S. Pat. No. 5,014,717 toLohrmann, issued May 14, 1991, describes a punch biopsy techniquecomprising a sleeve-shaped knife and a stylet which slides within theknife. All of these patents, incorporated herein by reference, andothers, disclose typical prior art techniques and apparatus forgathering and removing a biopsy sample of tissue for further examinationand review by a trained professional.

OBJECTS AND SUMMARY OF THE INVENTION

It is one object of this invention to provide a device for penetratingtissue, through intervening tissues to the precise target tissueselected for a medical action such as tissue ablation and optionalsubstance delivery, limiting this activity to the precise preselectedsite, thereby minimizing the trauma and achieving a greater medicalbenefit.

It is another object of this invention to provide medical probe deviceswith surgical biopsy device directly at the distal end thereof forselective tissue sampling from target tissues.

It is still another object of this invention to provide medical probedevices with a surgical biopsy device capable of obtaining a tissuesample from target tissue.

It is still another object of this invention to provide medical probedevices with a surgical biopsy device capable of obtaining a tissuesample from target tissue in conjunction with an integrated circuit orsemiconductor device capable of delivering direct microwave energy forselective ablation applications.

In summary, the device of this invention is a medical probe apparatuscomprising a catheter having a stylet guide housing with at least onestylet port in a side thereof and stylet guide means for directing aflexible stylet outward through at least one stylet port and throughintervening tissue to targeted tissues. The stylet guide has a biopsysample device or other tissue manifesting device at the distal endthereof to gather tissue or perform another operation at the point ofthe desired tissue such as emitting electromagnetic energy as ablativepower to target tissues. The stylets comprise thin elongated supportmeans, each support means being enclosed within a non-conductive sleeve,including means at the distal ends of said stylets for selectivelyemitting electromagnetic energy or for gathering a sample of said targettissue, or both, said electromagnetic energy being delivered as ablativepower to said target tissues, with the electromagnetic energy beingmicrowave energy. The non-conductive sleeves are mounted forlongitudinal movement on the respective support means to expose aselected portion of the stylet surface in the target tissue.

In another embodiment, a medical probe apparatus is disclosed comprisinga catheter having a stylet guide housing with at least one stylet portadjacent the distal end thereof, including stylet guide means fordirecting a flexible stylet outward through at least one stylet port andthrough intervening tissue to target tissues, with a stylet positionedin at least one of said stylet guide means, said stylet comprising athin elongated support means, and means at the distal end of said styletfor gathering a sample of said target tissue. The gathering meanscomprises a biopsy tissue sampler, said biopsy tissue sampler comprisinga biopsy needle means for gathering sample tissue cells, or a sharpenedbarbed tipped stylet for cutting and gathering said tissue sample, or aclam shell or jaw stylet for gathering said tissue sample. When thebiopsy tissue sampler comprises a clam shell or alligator tooth biopsydevice for gathering said tissue sample, said biopsy device is openedwhen deployed by the longitudinal movement of the support means, andbeing closed on said target tissue to thereby define said tissue samplewhen said biopsy device is withdrawn into said insulating sleeve.

Also the biopsy tissue sampler may comprise a harpoon tipped apparatusfor gathering said tissue sample. The biopsy tissue sampler wouldcomprise a core sampling apparatus for gathering said tissue sample,wherein said core sampling apparatus comprises a hollow tube having asharpened end for facilitating the penetration into and gathering ofsaid sample tissue. In addition, if said biopsy tissue sampler comprisesa hollow tube, having an aperture along the lateral side thereofadjacent the distal end of said tube, the tissue sample being drawn intosaid hollow tube by a negative pressure applied to said hollow tube,said tissue sample being excised from said target tissue when saidhollow tube is withdrawn into said insulating sleeve. The hollow tubemay be harpoon shaped, having an aperture therein and a sharpened tip tofacilitate the penetration into said target tissue.

Further the biopsy tissue sampler comprises a clam shell or alligatortooth apparatus for gathering said tissue sample, with said biopsydevice being opened when deployed by the longitudinal movement of saidsupport means, and being closed on said target tissue to thereby definesaid tissue sample when said biopsy device is withdrawn into saidinsulating sleeve.

Another embodiment also includes means at the distal end of said styletfor emitting electromagnetic energy, said emitting means being energizedselectively with said gathering means or independently therefrom. Heresaid means for emitting electromagnetic energy comprises a microwaveantenna and said gathering means comprises a biopsy tissue sampler, saidstylet emitting electromagnetic energy selectively with said biopsytissue sampler or independently therefrom. The antenna wire is curledaround said insulating sleeve from the proximal end to the distal end ofsaid insulating sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, reference may be hadto the following detailed description of the invention in conjunctionwith the drawings wherein:

FIG. 1 is an isometric view of an RF ablation catheter embodiment with afiber optic viewing accessory;

FIG. 2 is a fragmented cross-sectional view of a preferred catheter tipand styler guide housing of this invention;

FIG. 3 is distal end view of the catheter tip and style guide housingshown in FIG. 2;

FIG. 4 is a proximal end view of the unassembled catheter tip and styletguide housing shown in FIG. 2, showing the lumina for the componentsthereof;

FIG. 5 is a schematic view of one manner of stylet deployment into aportion of a prostate protruding into the urinary bladder;

FIG. 6 is an exploded view of the RF ablation catheter shown in FIG. 1;

FIG. 7 is an isometric view of the adjuster block and tension tubeassembly of the RF ablation catheter shown in FIG. 6;

FIG. 8 is a detailed view "A" of the tension tube connections shown inFIG. 7;

FIG. 9 is an exploded view of the sleeve and electrode slide blockassembly of the embodiment shown in FIG. 6;

FIG. 10 is a schematic view of a deployment of two stylets in a prostateshowing a stylet orientation for overlapping ablation zone method;

FIG. 11 is a side view of a stylet with a hollow core biopsy samplingapparatus;

FIG. 12 is a side view of a stylet with a harpoon-shaped biopsy samplingapparatus;

FIG. 13 is a side view of a harpoon-shaped biopsy sampling stylet;

FIG. 14 is a side view of a double action biopsy jaw sampling stylet;

FIG. 15 is an enlarged side view of the double action jaw samplingstylet of FIG. 14;

FIG. 16 is a side view of another embodiment of a biopsy sampling styletcombining a biopsy knife and an RF antenna;

FIG. 17 is a cross-sectional view of one section of the stylet shown inFIG. 16; and

FIG. 18 is a cross-sectional view of the distal end of the stylet shownin FIG. 16 combining the antenna probe and biopsy knife.

DETAILED DESCRIPTION OF THE INVENTION

The device of this invention provides a precise controlled positioningof a treatment stylet in a tissue targeted for treatment, ablation, orsampling from a catheter positioned in the vicinity of targeted tissues.

The term "stylet" as used hereinafter is defined to include both solidand hollow probes which are adapted to be passed from a catheter portthrough normal tissue to targeted tissues. The stylet is shaped tofacilitate easy passage through tissue. It can be a solid wire, thinrod, or other solid shape or it can be a thin hollow tube or other shapehaving a longitudinal lumen for introducing fluids to or removingmaterials from a site. The stylet can also be a thin hollow tube orother hollow shape, the hollow lumen thereof containing a reinforcing orfunctional rod or tube such as a laser fiber optic. The styletpreferably has a sharpened end to reduce resistance and trauma when itis pushed through tissue to a target site. As will be hereafterdescribed, the stylet can also include biopsy sample gathering, laserlight emitting, and microwave apparatus, as well.

The stylet can be designed to provide a variety of medically desiredtreatments of a selected tissue. As a resistance heater, radiofrequencyelectrode, laser light emitter, or microwave antenna, it can be used toablate or destroy targeted tissues. As a hollow tube, it can be used todeliver a treatment fluid such as a liquid to targeted tissues. Theliquid can be a simple solution or a suspension of solids, for example,colloidal particles, in a liquid. Since the stylet is very thin, it canbe directed from the catheter through intervening normal tissue with aminimum of trauma to the normal tissue. As a biopsy sample gatherer, asample specimen of target tissue may be taken and removed for furtherexternal histological analysis and examination.

The device and method of this invention provide a more precise,controlled medical treatment which is suitable for gathering ordestroying cells of medically targeted tissues throughout the body, bothwithin and external to body organs. The device and method areparticularly useful for treating benign prostate hyperplasia (BPH), andthe device and its use are hereinafter described with respect to BPH,for purposes of simplifying the description thereof. It will be readilyapparent to a person skilled in the art that the apparatus and methodcan be used to gather or destroy body tissues in any body cavities ortissue locations that are accessible by percutaneous or endoscopiccatheters, and is not limited to the prostate. Application of the deviceand method in all of these organs and tissues are intended to beincluded within the scope of this invention.

BPH is a condition which arises from the benign replication and growthof cells in the prostate, forming glandular and stromal nodules whichexpand the prostate and constrict the opening of the prostatic urethra.Glandular nodules are primarily concentrated within the transition zone,and stromal nodules within the periurethral region. Traditionaltreatments of this condition have included surgical removal of theentire prostate gland, digital removal of the adenoma, as well astransurethral resection of the urethral canal and prostate to removetissue and widen the passageway. One significant and seriouscomplication associated with these procedures is iatrogenic sterility.More recently, laser treatment has been employed to remove tissue,limiting bleeding and loss of body fluids. Balloons have also beenexpanded within the urethra to enlarge its diameter, with and withoutheat, but have been found to have significant limitations.

Microwave therapy has been utilized with some success by positioning amicrowave antenna within the prostatic urethra and generating heat inthe tissue surrounding the urethra with a microwave field. Coolants aresometimes applied within the catheter shaft to reduce the temperature ofthe urethral wall. This necessitates complicated mechanisms to provideboth cooling of the immediately adjacent tissues while generating heatin the more distant prostatic tissue. This technique is similar tomicrowave hyperthermia. Similarly, radiofrequency tissue ablation withelectrodes positioned within the urethra exposes the urethral wall todestructive temperatures. To avoid this, temperature settings requiredto protect the urethra must be so low that the treatment time requiredto produce any useful effect is unduly extended, e.g. up to three hoursof energy application.

One embodiment of the device of this invention previously disclosed in aparent application uses the urethra to access the prostate and positionsRF electrode stylets directly into the tissues or nodules to bedestroyed. The portion of the stylet conductor extending from theurethra to targeted tissues is enclosed within a longitudinallyadjustable sleeve shield which prevents exposure of the tissue adjacentto the sleeve to the RF current. The sleeve movement is also used tocontrol the amount of energy per unit surface area which is delivered bycontrolling the amount of electrode exposed. Thus the ablation isconfined to the tissues targeted for ablation, namely those causing themechanical constriction. Other aspects of the invention will becomeapparent from the drawings and accompanying descriptions of the deviceand method of this invention. It will be readily apparent to a personskilled in the art that this procedure can be used in many areas of thebody for percutaneous approaches and approaches through body orifices.

FIG. 1 is an isometric view of an ablation catheter embodiment of thisinvention with a fiber optic viewing accessory. The flexible catheter 2,attached to handle 4, has a terminal stylet guide 6 with two stylets 8.The handle has stylet sleeve tabs 10 and 11 and electrode tabs 12 and 13as will be described in greater detail hereinafter. The handle 4 is alsoconnected to a optical viewing assembly 14 and RF power connector 16,transponder connector 18 and thermocouple connectors 20. The portions ofthe catheter 2 leading from the handle 4 to the stylet guide tip 6 canoptionally have a graduated stiffness. For example, the catheter can bedesigned to be more stiff near the handle and more flexible near thetip, or any other stiffness profiles. The catheter can be constructed ofan inner slotted stainless steel tube with outer flexible sleeve such asis described in copending application Ser. No. 790,648 filed Aug. 11,1991 (corresponding to published Australian patent application Ser. No.9210858), the entire contents of which are incorporated herein byreference. It can also be made of coiled or braided wire to which anouter sleeve is bonded.

The fiber optic viewing assembly in this embodiment includes a lensfocusing assembly 22, a lens viewing assembly support connector 24assembly attached to a male quick disconnect connector 26 by flexibletubing 28.

FIG. 2 is a fragmented cross-sectional view of a preferred catheter tipand stylet guide housing of this invention. The solid catheter tip 106has a lateral depression or saddle 108 therein having a central axisapproximately perpendicular to a plane through the central axis of thetip. The depression 108 has a proximal wall 110. The depression 108 canextend up to approximately half of the thickness of the housing, but atleast sufficiently to unblock the viewing surface of the viewing tip 112of the fiber optic 114. The fiber optic viewing tip 112, when positionedat the opening in wall 110, provides a field of view with lateralmargins 116 and a terminal margin 118. This includes the path of styletsextended outward through ports 120.

FIG. 3 a distal end view of the catheter tip and style guide housingshown in FIG. 2. The proximal end of depression 108 is split to form twoprojections or ears 122 and 124 which define a longitudinal or axial orlongitudinal groove or saddle 126 extending from the depression 108 tothe terminal tip 128 of the catheter 106. Groove 126 opens the field ofview for the viewing tip 112 when in the solid line position shown inFIG. 2 and permits extension of the fiber optic and its tip through thelongitudinal groove to the dotted line positions 114' and 112'. In thelatter position, the field of vision has side margins 130 and a terminalmargin 132. This permits the operator to examine the inner duct surfacesahead of the catheter tip. In an alternative embodiment, the groove 126can be replaced with a hole in the end of the tip having a size andposition to permit extension of the fiber optic 114 therethrough.

The fiber optic 114 is positioned in a passageway 134 which issufficiently larger than the fiber optic to permit flow of flushingliquid around the fiber optic to the exit in wall 110. The flushingliquid flow clears debris from the viewing tip. The inner walls of theduct (not shown) surrounding the catheter tip 106 during use confine theliquid flow, so the liquid continues to pass over the fiber optic tipeven when it has been advanced to the dotted line position. Returnflushing liquid lumina 136 and 138 extend through wall 110 for constantremoval of contaminated flushing liquid.

FIG. 4 is a proximal end view of the unassembled catheter tip and styletguide housing shown in FIG. 2, showing the lumina for the componentsthereof. The stylets are advanced and retracted through stylet lumina140 and 142 to the stylet ports 120. The fiber optic is advanced andretracted through fiber optic lumen 134. The contaminated flushing fluidis removed through flushing fluid return lumina 136 and 138. Temperaturesensor lumen 144 is used to house leads of a temperature sensor (notshown).

FIG. 5 is a schematic view of a single stylet of FIG. 1 or 2 showndeployed to treat a portion of a prostate protruding into the urinarybladder. The solid catheter tip 196 is positioned at the end of theurethra 220. Cell proliferation in the upper end 222 of the prostate 224has caused it to protrude into space normally occupied by the urinarybladder, pushing a portion of the bladder wall 226 into the cavity andforming a restriction 225 beyond the end of the urethra. The styletsleeve 206 and electrode 204 are extended at an angle of about 30°through the urethral wall into a portion of the protruded prostate, andRF current is applied to form the lesion 228. This will reduce theprotruded prostate, promoting its retraction from the urethral wall andopening the restriction of the outlet end of the urethra. The catheterhaving a desired angle can be selected from those having predeterminedangles to precisely orient the stylet and effect precise penetration ofprostate tissue which extends beyond the end of the urethra, forexample.

FIG. 6 is an exploded view of the ablation catheter assembly shown inFIG. 1. The upper handle plate 276 has two central slots 278 and 280through which the electrode control slides 10 are attached to respectiveleft electrode slide block 282 and right electrode slide block 284.Sleeve control slides 12 and 13 are attached through outer slots 286 and288 to respective left sleeve slide block 290 and right sleeve slideblock 292. Fiber optic receptor housing 30 is mounted on the proximalsurface of the upper handle plate 276. The electrical receptor 294 isreceived in respective cavities 296 and 298 in the respective upperhandle plate 276 and lower handle plate 300 attached thereto. The lowerhandle plate 300 has a central cavity 302 which accommodates theelectrode and sleeve slide blocks and associated elements.

Microswitch activator blocks 304 (only left sleeve block shown) areconnected to the sleeve slide blocks 290 and 292. They are positioned toactuate the microswitches 306 when the respective sleeve block (andsleeve attached thereto) have been advanced. The microswitches 306 holdthe electromagnetic power circuits open until the respective sleeves areadvanced to a position beyond the urethra wall and into the prostate toprevent direct exposure of the urethra to the energized electrodes.Extension of the sleeve 5 mm beyond the guide is usually sufficient toprotect the urethra.

The tension-torque tube assembly 308 is mounted in the distal end of thehousing in the receptor 310.

FIG. 7 is an isometric view of the adjuster block and tension tubeassembly 308 of the ablation catheter shown in FIG. 6. The torque tube312 extends from the torque coupler 314 through the twist control knob316 to the stylet guide 6. Bending flexure of the torque tube 312 duringuse lengthens the path from the handle to the guide tip 6. To prevent aresulting retraction of the stylet sleeve and electrode components whenthe torque tube 312 is flexed, a tension tube 318 having a fixed lengthand diameter smaller than the inner diameter of the torque tube 312 isprovided. The distal end of the tension tube 318 is securely attached tothe stylet guide 6, and the proximal end 320 is secured to the adjusterblock 322, for example by an adhesive. The axial or longitudinalposition of the adjuster block 322 can be adjusted to insure the styletsare initially positioned just inside the outlet ports in the styletguide 6. Torque coupler 314 is mounted on the coupler block 324. Twistcontrol knob stop pin 326 extends into a groove (not shown) and limitsrotation of the control knob 316.

FIG. 8 is a detailed view "A" of the distal end tension tube connectionsof the tension tube shown in FIG. 7. The tension tube 318 is securelyconnected to the proximal end 328 of the stylet guide 6, for example bya length of shrink tubing 330.

FIG. 9 is an exploded view of the sleeve and electrode slide blockassembly of the embodiment shown in FIG. 6. The right sleeve slide block292 has a projection 332 which extends inward under the right electrodeslide block 284. Right sleeve connector 334 is mounted to the inner endof the projection 332, secured to the end of the proximal end of thesleeve 336. Right electrode connector 338 is attached to an innersurface of the electrode slide block 284 and is secured to the proximalend of electrode 340. The right sleeve and electrode slide blocks 292and 284 are slidingly attached to the right friction adjustment rail 342by screws (not shown) through slots 344 and 346, the screws beingadjustable to provide sufficient friction between the blocks and therail 342 to provide secure control over the stylet movement. The leftsleeve slide block 290 and left electrode slide block 282 are mirrorreplicas of the right blocks and are similarly mounted on the leftfriction rail 345. The left sleeve and electrodes are not shown.

FIG. 10 is a schematic view of a deployment of two stylets in a prostateshowing stylet orientation for overlapping ablation zone method of thisinvention as provided, for example, by RF current, or a microwave field.For purposes of illustration, but not by way of limitation, the prostatehas been selected for this explanation, and application of this methodand assembly to other areas of the body are intended to be included.

The tissues to be treated for the treatment of BPH are located in thetransition zone 428 of the prostate. A catheter of this invention 430has been inserted up the urethra 432 to a position adjacent theprostate. Two stylets 434 and 436 have been passed through the urethrawall 432 through forward movement of tabs 10 and 12 (FIG. 1) and throughsurrounding tissue into targeted tissues. The non-conducting sleeves 438and 440 have been retracted by rearward movement of sleeve tabs 10 toexpose a portion of the respective electrical conductors 442 and 444 atthe end of each stylet. The angle between the axes of the stylets inthis embodiment is less than 180°, preferably less than 110°. For mostoverlapping ablations, angles of 15° to 90°, and more usually from 20°to 70° are most practical. A grounding plate (not shown) is placed onthe body exterior.

When electrodes 442 and 444 are supplied with RF current, the circuitfrom the electrodes to a grounding plate is closed. The current densityflowing through the tissue passes through targeted tissues to betreated, creating lesions having the approximate cross-sectional shapeof overlapping zones 446 and 448. The current density rapidly decreasesas a function of distance, limiting the size of the lesions. In thismanner, lesions can be caused to overlap to form a larger lesion,increasing the efficiency of the treatment. It will be readily apparentthat these processes can be carried out concurrently, as described, orsequentially, and these variations are intended to be included in thisinvention.

While the invention described above has utility in the treatment ofbenign prostate hyperplasia, in some instances a physician may desire toproceed further and actually determine if the prostate contains anycancerous tissue. While the ablation technique described above iseffective against BPH, other, and possibly more drastic, procedures maybe necessary in the happenstance that the prostate is cancerous. In thepossibility that the physician believes that the prostate is cancerous,or contains cancerous tissue or nodules, he or she may desire to examinethe suspected tissue by taking a sample of the tissue for histologicalexamination.

The disclosure herein regarding biopsy and tissue gathering of theprostate is not intended to limit the scope of the invention. Theprinciples of the disclosed invention also have utility andapplicability to other body tissues.

FIG. 11 is a side view of a core sampling biopsy stylet 1100. As seen inFIGS. 5, 6, and 7, the stylet comprises a sleeve and an operatingelectrode. In this embodiment, the electrode has been substituted by thecore sampling hollow tube 1102 which is enclosed in sleeve 1104.Sharpened tip 1106 of sleeve 1104 matches the shape of tip 1108 the coresampler stylet 1102. This sharpened edge allows for easier penetrationof the tissue leading up to and including the target tissue. After thecatheter shown in the previous figures is inserted into the urethra, orother body opening, the sleeve 1104 is extended from the catheter intothe urethra wall and into the prostate gland by use of the appropriatestylet sleeve tab 10 or 11 as seen in FIG. 1. At the proper time, thestylet 1102 is extended out of the sleeve 1104 by action of eitherelectrode tabs 12, 13 in FIG. 1. Upon deployment of stylet 1102, atissue specimen will be cut by the sharp tip 1108 and will be collectedin the hollow distal end portion 1114. If desired, the stylet 1102 couldbe revolved or oscillated around its longitudinal axis to facilitate thecutting action thereof. The core sample stylet 1102 can then bewithdrawn into the sleeve 1104, the sleeve 1104 withdrawn into thecatheter, and then the catheter completely withdrawn from the body. Thebiopsied tissue can be withdrawn from the core 1114 of tube 1102 andexamined by a medical professional for signs of BPH or cancer,

FIG. 12 is a side view of a biopsy sampler stylet assembly 1200 with aharpoon-blade stylet structure 1204. Sleeve 1208 terminates in a forwardend 1210 which is tapered to form a blade type surface. Stylet shaft1204 extends through the sleeve 1208 and terminates in theharpoon-shaped structure generally shown at 1206. A harpoon is a barbed,spear-like device which is difficult to remove from a target animal ortissue due to the barbed tip. In this instance, the harpoon-bladestructure 1206 is a cylindrical tube 1204 with side port or pocket 1202as a receptor for gathered tissue. The back of the harpoon 1206 wouldhave sharp, cutting edge 1214. The harpoon-blade structure may beoriented in any manner relative to the taper on the sleeve 1208 atforward end 1210, as long as the sharp harpoon edge 1214 causes asevering action when drawn back into the sleeve 1208 past the edge 1210.The harpoon end 1206 also includes a tip 1216 which is used to puncturethe tissue which is to be sampled, and a pocket 1202 formed behind theharpoon-type barb 1206.

Once the catheter is inserted into the urethra, the sleeve 1208 isextended from the catheter (see FIG. 5) into the urethra wall and intothe prostate gland by the use of the appropriate stylet sleeve tab (seeFIG. 6). Then stylet 1204 would be deployed into the prostate at thedesired target tissue. The positioning of the harpoon tip 1206 relativeto the forward end 1210 of sleeve 1208, such that upon movement of theappropriate sleeve block, the harpoon stylet 1204 moves forward of end1210 and can be withdrawn into the opening formed by forward edge 1210of sleeve 1208. Upon withdrawal of the harpoon stylet assembly 1204 intosleeve 1208, the sharp edge 1214 will sever any tissue that expandedinto pocket 1202. As the stylet 1204 is further withdrawn rearwardlyinto sleeve 1208, the tissue sample will be retained in the pocket 1202of harpoon 1206 within sleeve 1208. Then, similarly to the embodimentabove in conjunction with FIG. 11, the sleeve 1208 is withdrawn from thepatient's body and the tissue removed from pocket 1202 for externalhistological examination.

FIG. 12 is a side view of one embodiment of this aspect of the inventionwith the pointed edge 1216 leading back at an angle to the cutting edge1214. While FIG. 13 is a side view of a second embodiment of this aspectof the invention wherein the sharp edge 1216 is substantially parallelto the leading edge 1210 of sleeve 1208. However, cutting edge 1214would operate in a similar manner as the embodiment shown in FIG. 12 tocut a sample tissue to be retained in pocket 1202.

FIGS. 14 and 15 are side views of still another biopsy sampler styletassembly 1300 where target tissue samples are obtained by the action ofclam shell or alligator-type jaws 1302. The jaws depicted in FIG. 13 areof the double action type which include the jaws 1302 pivoted aboutpoint 1304. Comprising jaws 1302 are jaw 1306 and jaw 1308. Jaw 1306 andjaw 1308 are connected via a flexible pivot point 1302. At the forwardend of each jaw 1306, 1308 would be alligator type teeth (not shown) forgripping and/or cutting the desired tissue. Alternatively, the forwardends of the jaws 1306, 1308 could be very sharp as to facilitate acutting action upon deployment and operation of the biopsy jaws 1302.

At the other ends of both jaws 1306 and 1308 are attached arms 1316 and1314 via pivots 1312 and 1310. Within the stylet sleeve 1320 ispositioned the stylet cable 1322. Pivot point 1304 is present in thedistal end of the stylet 1322 to support and operate the jaws 1302 upondeployment of the apparatus into the target tissue. When the cable 1324is withdrawn by the operating surgeon, the arms 1314 and 1316 are pulledtoward the operator which, by the double jaw action about pivot point1304, closes jaws 1302. When jaws 1306 and 1308 come together, the sharpforward edges thereof will cut off or sever a small sample of targettissue. The stylet jaw assembly 1302 is then withdrawn into sleeve 1320,the sleeve withdraws from the tissue, and the tissue sample withdrawnand removed from the patient's body for external histologicalexamination.

FIGS. 16 to 18 show a biopsy knife sampler stylet 1400 in combinationwith an RF antenna arrangement. FIG. 16 shows the stylet 1404 surroundedby sleeve 1402. Sharpened edge 1406 of the stylet 1404 aids in insertioninto the selected body tissue. Wound about the central stylet 1404 isantenna wire 1408 which would be connected via antenna connector 1410 toa source of high frequency signals. If the arrangement 1400 is used as amicrowave antenna as set forth in FIGS. 17 and 18, then the signalsapplied would be in the microwave frequency range (for example, from 915MHz to 2.45 GHz. If the stylet arrangement 1400 is used as an RF (radiofrequency) current generator to a separate body contact electrode, notshown, then the high frequency signal source would be in the range of 10to 20 MHz.

FIG. 17 depicts an enlarged cross-sectional view B of the styletarrangement shown in FIG. 14a. Hollow lumen 1404 is seen to be enclosedby dielectric insulating sleeve 1402. The antenna wire 1408, which iswound into the hollow lumen 1404, is shown in various positions incross-section.

FIG. 18 is an enlarged cross-sectional representation of the embodimentof a biopsy stylet according to this invention as shown above inconjunction with FIG. 16. This stylet comprises a flexible tube 1404having an electrode wire 1408 embedded in the surface thereof. Theelectrode wire is enclosed with a retractable insulating sleeve 1402. Atthe end of the tube 1404, a biopsy knife 1412 with a cutter tip 1412extends through a flexible clamshell or resilient shield 1414. Duringadvancement of the biopsy stylet, the shield 1414 is closed, and thebiopsy knife 1412 is in a retracted position behind the shield. When thebiopsy knife is advanced, the sharp cutter tip 1418 passes throughshield and penetrates tissue with a minimum of trauma. The cutter tip1418 has a side opening 1420 through which a sample of tissue or liquidcan be aspirated through concentric suction tube 1422. Retraction ofbiopsy knife 1412 permits the shield 1414 to close to its initialposition, shielding tissue from the sharp edge 1418.

In operation, the catheter would be inserted in the urethra in themanner set forth above. The sleeve 1402 would then be selectivelydeployed by the physician into the target tissue. Then the lumen 1404with the antenna wire 1408 would be extended out from lumen 1404 intothe target tissue. At this point the physician has several options.She/he could then selectively deploy the biopsy knife 1412 into thetarget tissue to gather sample tissue for later examination. Or thephysician could ignore the biopsy knife 1412 and energize, as set forthabove, the extended antenna probe 1414 to heat and thus ablate thesurrounding tissue. Or the physician can operate both aspects of thisembodiment in the order of the physician's choice. That is, the biopsyknife 1412 can be deployed to gather a target tissue sample. The biopsyknife could be withdrawn through the hollow lumen 1404 and out from thepatient's body for external histologic examination. If the tissuecontains evidence of cancer, or BPH tissue, the physician could thenchoose to actuate the microwave aspect of this embodiment to ablate theselected target tissue. In this embodiment choice, the hollow lumen andcatheter would remain in the body while the biopsy knife arrangement1412 is completely withdrawn for external examination. Lastly, the thirdoption for the physician is to actuate the microwave antenna 1414 toablate the target tissue, then deploy the biopsy knife 1412 to take atissue sample for external examination and review. This embodiment isparticularly advantageous to the physician and the patent, as thedetection, examination, and ablation of the selected tissue can occurwith only one insertion of the catheter and stylet arrangement.

While the invention has been described with reference to specificpreferred embodiments, it will be understood by those skilled in the artthat various changes may be made and equivalents may be substituted forelements thereof without departing from the true spirit and scope of theinvention. In addition, many modifications may be made without departingfrom the essential teachings of the invention.

What is claimed is:
 1. A medical probe apparatus comprising a catheterhaving a stylet port toward the distal end thereof, a flexible styletdisposed within the catheter and having a sharp distal end forpuncturing tissue, means for advancing the stylet through the styletport and through intervening tissue to target tissue, means near thedistal end of the stylet for cutting and collecting a sample of thetarget tissue, and means at the distal end of the stylet for emittingelectromagnetic energy.
 2. The medical probe apparatus of claim 1wherein the means for emitting electromagnetic energy comprises amicrowave antenna, and the means for cutting and collecting a sample ofthe target tissue comprises a biopsy tissue sampler.
 3. The medicalprobe apparatus of claim 1 wherein the means for emittingelectromagnetic energy is selectively energizable either with the meansfor cutting and collecting a sample of the target tissue orindependently thereof.
 4. In a sampling probe: an elongated flexiblestylet having a sharp distal end for puncturing tissue, means forguiding the distal end of the stylet through the urethral wall and intothe prostatic tissue near the urethral wall, and means carried by thestylet for cutting and collecting a sample of the prostatic tissue. 5.The sampling probe of claim 4 further including means disposed towardthe distal end of the stylet and coupled to a source of electromagneticenergy for emitting electromagnetic energy into the prostatic tissue. 6.The sampling probe of claim 4 wherein the distal end portion of thestylet comprises a hollow tube.
 7. The sampling probe of claim 6 whereinthe means for cutting and collecting the sample comprises an opening ina side wall of the tube with a cutting edge on one side of the opening.8. The sampling probe of claim 7 wherein the cutting edge faces in arearward direction from the distal end of the stylet.
 9. The samplingprobe of claim 7 further including a sleeve disposed coaxially about thedistal end portion of the stylet, with the stylet and the sleeve beingmovable relative to each other between a first position in which theopening is exposed to the tissue and a second position in which theopening is covered by the sleeve.